Analysis of the efficiency of a combined tuned damper with uncertainty in the parameters subject to a high frequency content seismic excitation

Abstract

This research studies the behavior of the optimal parameters and the efficiency of the Tuned Combined Damper (TCD) in the control of a structure subjected to seismic excitation, when uncertainty is incorporated in the mass ratio and the length ratio. The TCD is a device made up of a tuned liquid column damper (TLCD), and a tuned mass damper (TMD). Seismic excitation is modeled as a stationary type zero-mean Gaussian stochastic process. It is considered a seismic excitation with a high frequency content. The equivalent statistical linearization method is used to linearize the nonlinear equation associated with the tuned fluid damper. The sensitivity of the optimal parameters, the tuning ratio and the head loss coefficient of the TLCD, and the tuning and damping ratio of the AMS are analyzed by including an uncertainty in the mass ratio and the length ratio. Reduction of displacement of the main structure is used as optimization criterion. The TCD efficiency and root mean square RMS of the main system displacement are obtained. The results show that the most sensitive parameter is the head loss coefficient, when faced with an uncertainty in the length ratio. It is concluded that the efficiency of the TCD and RMS of displacement of the main structure is insensitive to an uncertainty of less than 10%, both of the mass ratio and the length ratio.